After several months of just not listening to my 2 meter base station, I
finally took time to find the source of the interference that held the
squelch open on the repeater channel I listen to most often. Turned out it
was my Dlink DI-604 router. I borrowed a Linksys NR-041 router from my
neighbor and it works a little better. I can now listen to the 145.390
repeater, not because the Linksys puts out no RFI, but only because it puts
it out in a different place (mostly in the 146.46-146.58 range). I will
probably invest in a newer router, probably wireless. Question I have is
does anyone have any experience with the new breed of wireless routers that
are reasonable clean in the RFI/2 meter spectrum? Thanks.

In article ,
Jim Leder wrote:

After several months of just not listening to my 2 meter base station, I
finally took time to find the source of the interference that held the
squelch open on the repeater channel I listen to most often. Turned out it
was my Dlink DI-604 router. I borrowed a Linksys NR-041 router from my
neighbor and it works a little better. I can now listen to the 145.390
repeater, not because the Linksys puts out no RFI, but only because it puts
it out in a different place (mostly in the 146.46-146.58 range). I will
probably invest in a newer router, probably wireless. Question I have is
does anyone have any experience with the new breed of wireless routers that
are reasonable clean in the RFI/2 meter spectrum? Thanks.

Back in August I helped my city's ARES/RACES EC chase down a 2-meter
interference problem at his condo. An HP spectrum analyzer showed a
whole series of regularly-spaced spurs throughout the 2-meter band -
most strong enough to de-squelch an HT, and several strong enough to
compete with repeater-output signals on the same or nearby frequencies
and make communication difficult or impossible. He had the usual
"cable channel 18" spur on 145.250 (not a new problem at his QTH) but
the multiple spurs were something new.

By plugging a measuring-tape Yagi-Uda foxhunt antenna into the spectrum
analyzer, we quickly localized the source of the signal to the
neighboring condo unit, second floor, rear of the building, polarized
45 degrees from vertical :-)

He spoke with his neighbor, and they quickly identified the neighbor's
new Netgear 802.11b/g WAP/router/switch as the cause. We did some
RF-snooping with the spectrum analyzer and a rubber duck, and
determined that the spurs were radiating from within the router's case
itself. The source seemed to be on the right side of the case, just
in front of the DC power inlet jack. There was no significant spur
radiation from the power cord itself - it was coming from the PC
board, and whatever ferrites or whatever Netgear had put on the DC
inlet were doing their job just fine.

My conclusion was that the Netgear model in question uses a buck-mode
switching voltage regulator, operating at a switching frequency of
about 30-40 kHz (the spacing of the spurs we saw), and that its
internal switch generates very fast current rise/fall times which
radiate harmonics from the PC board.

I ran a similar test on an older model of Netgear wireless router (one
of a couple I'd picked up at a swap meet) and observed no such
problem. The older router's switcher does emit some low-level 2-meter
hash into a nearby probe, but it's much less energetic and appears as
broadband RF noise with no significant peaks. Possibly the older unit
has a spectrum-spreading feature in its regulator, or possibly it's
just a better design RF-wise (slower switching edges, self-shielding
inductors, better grounding/routing on the board, etc.).

The noisy router is a Netgear model WGR614 v6 (802.11b/g), FCC ID
PY305100002.

The non-noisy one is a Netgear model MR814 v2 (802.11b), FCC ID
PY3MR814v2.

My EC's neighbor (a retired EE who takes Part 15 quite seriously) went
out and bought a different model of b/g router, and the problem went
away. I'm afraid I don't know the number of the replacement model.

Given how frequently manufacturers revise their hardware (every time
their OEM gets a new batch of parts, I suspect) I think you're
probably going to have to test individual models for acceptable QRM
levels. A model number which looks OK today, might or might not have
the same guts in it as a unit of the same model number that you buy
three months from now.

A year or so before that, a few other guys and I used the same HP
spectrum analyzer to locate the source of some QRM which was causing a
buzzing squelch-tail interference on numerous local 2-meter repeaters.
It turned out to be a Netgear 4-port wired-Ethernet hub, which was
howling like a whole chorus of dire wolves on a high-order harmonic of
its (drifty) internal crystal's frequency. The signal was apparently
getting into all of the 10BaseT wiring and back out the power cord
into the mains... his whole apartment was radiating. From a block
away we could "see" when the owner started to download files from the
Internet, thanks to the strong pulsing spur which would appear
somewhere in the 2-meter band.

I offered him one of my spare 6-port hubs (an Airlink) in return for
his defective unit, he agreed, we made the exchange. Problem solved,
hasn't returned.

--
Dave Platt AE6EO
Hosting the Jade Warrior home page: http://www.radagast.org/jade-warrior
I do _not_ wish to receive unsolicited commercial email, and I will
boycott any company which has the gall to send me such ads!

Hmmm, I have the same router, with no problems at all, and it is about 1
meter from my radios.... try winding the power cord together in one
bundle, and use it at 100 tx/rx with Cat5e or better cables. From my
router, the wan goes to a DSL box, and the lan is hooked up to a Gigabit
switch, and a 10/100 switch, all with no interference noticeable..

Jim Leder wrote:
After several months of just not listening to my 2 meter base station, I
finally took time to find the source of the interference that held the
squelch open on the repeater channel I listen to most often. Turned out it
was my Dlink DI-604 router. I borrowed a Linksys NR-041 router from my
neighbor and it works a little better. I can now listen to the 145.390
repeater, not because the Linksys puts out no RFI, but only because it puts
it out in a different place (mostly in the 146.46-146.58 range). I will
probably invest in a newer router, probably wireless. Question I have is
does anyone have any experience with the new breed of wireless routers that
are reasonable clean in the RFI/2 meter spectrum? Thanks.



--
Bob N9LVU

One more thing you might try, is to line the inside with aluminum foil
thats at ground potential...
I have just checked mine for rf emissions using my Standard C168A as it
has a very good front end. I have found that I get more rf from my
laptop(s, than my desktop(s)/server(s)that have all metal cases. There
is very little from my network connections..

Jim Leder wrote:
After several months of just not listening to my 2 meter base station, I
finally took time to find the source of the interference that held the
squelch open on the repeater channel I listen to most often. Turned out it
was my Dlink DI-604 router. I borrowed a Linksys NR-041 router from my
neighbor and it works a little better. I can now listen to the 145.390
repeater, not because the Linksys puts out no RFI, but only because it puts
it out in a different place (mostly in the 146.46-146.58 range). I will
probably invest in a newer router, probably wireless. Question I have is
does anyone have any experience with the new breed of wireless routers that
are reasonable clean in the RFI/2 meter spectrum? Thanks.



--
Bob N9LVU

In article ,
"Jim Leder" wrote:

After several months of just not listening to my 2 meter base station, I
finally took time to find the source of the interference that held the
squelch open on the repeater channel I listen to most often. Turned out it
was my Dlink DI-604 router. I borrowed a Linksys NR-041 router from my
neighbor and it works a little better. I can now listen to the 145.390
repeater, not because the Linksys puts out no RFI, but only because it puts
it out in a different place (mostly in the 146.46-146.58 range). I will
probably invest in a newer router, probably wireless. Question I have is
does anyone have any experience with the new breed of wireless routers that
are reasonable clean in the RFI/2 meter spectrum? Thanks.

I've heard from more than one source regarding D-link routers causing
interference. Seems the switching PS is causing problems in HF radios.
The company says it does not have a problem.

I use a Asante router and it is quiet.

"Big Endian" wrote in message
...
In article ,
"Jim Leder" wrote:

After several months of just not listening to my 2 meter base station,
I
finally took time to find the source of the interference that held the
squelch open on the repeater channel I listen to most often. Turned out
it
was my Dlink DI-604 router. I borrowed a Linksys NR-041 router from my
neighbor and it works a little better. I can now listen to the 145.390
repeater, not because the Linksys puts out no RFI, but only because it
puts
it out in a different place (mostly in the 146.46-146.58 range). I will
probably invest in a newer router, probably wireless. Question I have is
does anyone have any experience with the new breed of wireless routers
that
are reasonable clean in the RFI/2 meter spectrum? Thanks.

I've heard from more than one source regarding D-link routers causing
interference. Seems the switching PS is causing problems in HF radios.
The company says it does not have a problem.


I replaced a Linksys 4 port router with a Belkin to get a spur off the local
repeater. It was so strong I could not squelch it out. Not sure where the
Belkin puts the spurs if it has them.

On 2005-12-22, Jim Leder wrote:
squelch open on the repeater channel I listen to most often. Turned out it
was my Dlink DI-604 router.

Does it happen with no network cables hooked up? If not, try some shielded
CAT5 cables (they have a foil layer in the cable and a metal shell over the
RJ45 connector).

--
Ben Jackson

http://www.ben.com/

In article . net,
"Ralph Mowery" wrote:

"Big Endian" wrote in message
...
In article ,
"Jim Leder" wrote:

After several months of just not listening to my 2 meter base station,
I
finally took time to find the source of the interference that held the
squelch open on the repeater channel I listen to most often. Turned out
it
was my Dlink DI-604 router. I borrowed a Linksys NR-041 router from my
neighbor and it works a little better. I can now listen to the 145.390
repeater, not because the Linksys puts out no RFI, but only because it
puts
it out in a different place (mostly in the 146.46-146.58 range). I will
probably invest in a newer router, probably wireless. Question I have is
does anyone have any experience with the new breed of wireless routers
that
are reasonable clean in the RFI/2 meter spectrum? Thanks.

I've heard from more than one source regarding D-link routers causing
interference. Seems the switching PS is causing problems in HF radios.
The company says it does not have a problem.


I replaced a Linksys 4 port router with a Belkin to get a spur off the local
repeater. It was so strong I could not squelch it out. Not sure where the
Belkin puts the spurs if it has them.

Also, be sure to either wire yourself or buy the straight through
ethernet cables that are wired for the 568-A standard, CAT 5E, enhanced.
Makes a big difference in long runs for connectivity and maybe in RFI.
They will tell you there is no difference in operation between a 568-A
and 568-B, but I can tell you from personal experience there is.

Thanks for all the suggestions, I do appreciate the input. I think Dave hit
the nail on the head, namely that all routers will PROBABLY generate
something, some worse than others. Dave, I read your reply over and over and
I am quite amazed at the tenacity you went after your problem. Didn't sound
like an easy bug to chase.
Now on to what I did to MINIMIZE my RFI problem. I say minimize because
it's not totally eliminated, but it's at a point where I can tolerate it.
My DSL modem and router are about 10 feet apart and I make all my own
cables, so I know they are made correctly. I attempted removing all 4 to see
if one of the cables to a PC was at fault and none of them were, however
when I removed the shorty cable between the modem and the router, the noise
stopped (the cable is only about 20 inches long). I tried all kinds of
things ( and yes, I did put a 6 foot cable in to get away from near
resonance on 2 meters), like wrapping the cable in foil, making it into a
ball and just moving it around in different positions, etc., but when I used
an iron core bead on the ROUTER end and wrapped as much of the cable around
it as I could, the problem all but disappeared. Putting the iron at the
modem end had no effect. The other thing I did was work an even trade of my
old Dlink router with my neighbor for his old Linksys router. The Linksys is
in a solid aluminum case (well shielded) and initially helped my problem.
This little Linksys has NO plastic on the outside and seems to be a bit
quieter because of it.
Lastly, I have all my antennas either outside or 20 feet away up in my
attic and on 2, all were affected. I will admit that if I put a rubber
duckie on my TS2000 and listen on 2, it was really bad. So the outside, more
distant antennas do help. I've only noticed this problem on 2 meters, no
where else. HF and 440 seem to be clean.
As Dave suggested, the problem is indeed coming from the routers, whether
it be the power supply or just the electronics of Ethernet, I'm not sure.
I'm guessing the electronics of the Ethernet is generating the spurs.
I think the Dlink DI-604 is a fine router, it has given me years of perfect
service but it looks like time to make a change. I may end up going through
several different wireless routers before finding that fits my operation,
but I always have the Linksys to fall back on.
Hope this discussion can help others.
Thanks again for the really great suggestions and Happy Holidays to all.

Jim Leder ... K8CXM since 1962


"Jim Leder" wrote in message
...
After several months of just not listening to my 2 meter base station, I
finally took time to find the source of the interference that held the
squelch open on the repeater channel I listen to most often. Turned out it
was my Dlink DI-604 router. I borrowed a Linksys NR-041 router from my
neighbor and it works a little better. I can now listen to the 145.390
repeater, not because the Linksys puts out no RFI, but only because it
puts it out in a different place (mostly in the 146.46-146.58 range). I
will probably invest in a newer router, probably wireless. Question I have
is does anyone have any experience with the new breed of wireless routers
that are reasonable clean in the RFI/2 meter spectrum? Thanks.

On Thu, 22 Dec 2005 14:57:29 -0500, "Jim Leder"
wrote:

My Linksys wireless router causes nothing at all on any of my vhf
equipment.





After several months of just not listening to my 2 meter base station, I
finally took time to find the source of the interference that held the
squelch open on the repeater channel I listen to most often. Turned out it
was my Dlink DI-604 router. I borrowed a Linksys NR-041 router from my
neighbor and it works a little better. I can now listen to the 145.390
repeater, not because the Linksys puts out no RFI, but only because it puts
it out in a different place (mostly in the 146.46-146.58 range). I will
probably invest in a newer router, probably wireless. Question I have is
does anyone have any experience with the new breed of wireless routers that
are reasonable clean in the RFI/2 meter spectrum? Thanks.